JP2001089968A - Antimicrobial acrylonitrile-based fiber having photocatalytic activity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antimicrobial acrylonitrile-based fiber having so called photocatalytic activity, capable of enhancing antimicrobial properties by light irradiation without increasing the amount of an antimicrobial metal compound. SOLUTION: This antimicrobial acrylonitrile-based fiber having photocatalytic activity is provided by heat treating an antimicrobial metal compound-containing acrylonitrile-based fiber in a range of pH 1-6. By this method the antimicrobial acrylonitrile-based fiber excellent in antimicrobial performance and having photocatalytic activity is provided and applications to clothing, night clothes, interior goods, living materials and the like are expected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial acrylonitrile fiber having a so-called photocatalytic activity, in which the antibacterial property is remarkably improved under the conditions of light.

[0002]

2. Description of the Related Art In recent years, with the maturation and aging of society and the tendency for a rich and comfortable living environment, the maintenance of health,
There is an increasing demand for enhancement, and there is a demand for clothing, bedding, interior products, living materials, and the like having clean and comfortable antibacterial performance.

[0003] As one of the methods for imparting antibacterial performance, it is known that silver ions or copper ions exhibit excellent antibacterial properties, and the properties of these metal ions are used to impart antibacterial properties to fibers. There are known ways to do this. For example, Japanese Patent Application Laid-Open No.
As described in JP-A-2-92000 and JP-A-3-199418, sulfonic acid groups, carboxylic acid groups,
In an acrylic fiber having an ion-exchange group such as a hydroxyl group, an antibacterial acrylonitrile system in which silver ions or copper ions are bonded to part or all of the ion-exchange groups to be left as metallic silver, copper or a compound of the metal. Means for providing fibers are mentioned.

However, such a method has a certain level of antibacterial properties, but cannot sufficiently meet the recent demand for antibacterial properties.
There is a problem that the amount of silver or copper ions contained in the antibacterial acrylonitrile fiber must be increased.

[0005]

An object of the present invention is to provide an antibacterial acrylonitrile fiber having a so-called photocatalytic activity, which can enhance antibacterial properties by light irradiation without increasing the amount of an antibacterial active metal compound. It is in.

[0006]

Means for Solving the Problems The present inventors have intensively studied means for improving the antibacterial properties of antibacterial fibers. As a result, they have found that the above-mentioned problems can be solved by subjecting the acrylonitrile-based fiber containing the antibacterial active metal compound to a heat treatment within a pH range of 1 to 6, thereby completing the present invention. That is, the present invention resides in an antibacterial acrylonitrile-based fiber having photocatalytic activity obtained by subjecting an acrylonitrile-based fiber containing an antibacterial active metal compound to a heat treatment in a pH range of 1 to 6.

It is another object of the present invention to provide an antibacterial acrylonitrile fiber having photocatalytic activity, wherein the antibacterial active metal compound is a silver compound, the acrylonitrile fiber has an anionic functional group, ,
It is preferably achieved by a wet heat or dry heat of 100 to 160 ° C.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The acrylonitrile-based fiber containing the antibacterial active metal compound used in the present invention is a fiber formed from an acrylonitrile-based polymer, and is not particularly limited as long as it contains the antibacterial active metal compound. For the coalescence, it is possible to use a copolymer of acrylonitrile with 60% by weight or more, more preferably 80% by weight or more and a known monomer.

The comonomer used in the copolymerization is not particularly limited as long as it can be copolymerized with acrylonitrile, such as other polymerizable unsaturated vinyl compounds. Examples thereof include vinyl esters such as vinyl acetate; vinyl chloride and vinyl bromide. ,
Vinyl halides or vinylidenes such as vinylidene chloride; lower alkyl esters of (meth) acrylic acid such as methyl acrylate and methyl methacrylate (hereinafter, the description of (meth) acryl represents both acryl and methacryl) Acrylamide, styrene, sodium methallyl sulfonate, 2-acrylamide-2-
Sulfonic acid group-containing monomers such as methylpropane sulfonic acid, sodium p-styrene sulfonic acid, and sodium vinyl sulfonic acid, and carboxylic acid group-containing monomers such as (meth) acrylic acid and maleic acid can be used. In order to efficiently contain the antimicrobial active metal compound, it is desirable to contain 0.1 to 20% by weight of an anionic functional group-containing monomer such as a sulfonic acid group or a carboxylic acid group-containing monomer.

The antimicrobial active metal compound is not particularly limited as long as it is a metal compound having antimicrobial activity, but is preferably a silver compound in order to effectively impart photocatalytic activity. Here, the amount of the antibacterial active metal compound to be contained in the fiber in the present invention is not particularly limited, but is more preferably 1 to 200 m as a metal ion with respect to the fiber.
-It is good to contain mol / kg. That is, the content of the metal compound is different depending on the required antibacterial level, and if the content is less than the lower limit of the range, it is difficult to obtain a photocatalytic activity to be seen in a living environment and sufficient antibacterial performance associated therewith. In the case where the ratio exceeds 1, the problem that the fibers are markedly colored in a heat treatment step such as drying tends to occur. Further, since antibacterial performance accompanying sufficient photocatalytic activity for daily use or industrial use is permanently obtained within the above range, including the antibacterial agent beyond the above-mentioned range unnecessarily increases cost and industrially. Not advantageous.

The method for incorporating the antibacterial active metal compound into the acrylonitrile fiber is not particularly limited. For example, the method disclosed in JP-A-3-199418, that is, the method for producing acrylonitrile fiber, A method in which a gel structure fiber before a thermal relaxation step is continuously treated with an aqueous solution of an antibacterial active metal salt to cause the fiber to contain an antibacterial active metal compound, disclosed in JP-A-52-92000 and JP-A-7-243169. After the acrylonitrile fiber is manufactured by a conventional method, the antibacterial metal compound is contained by post-processing.

In the present invention, the acrylonitrile fiber containing the antibacterial active metal compound thus obtained is
It is necessary to perform the heat treatment within the range of pH 1 to 6, preferably pH 2 to 4. The method of the heat treatment is not particularly limited, but a method of performing treatment with wet heat or dry heat at 100 to 160 ° C is preferable. For example, acrylonitrile-based fibers containing an antibacterial active metal compound can be treated with a pH of 1 to 1.
And a method in which the fiber which has been dipped and drained in the acidic aqueous solution of No. 6 is subjected to wet heat treatment with steam in an autoclave, or a method in which the drained fiber is subjected to dry heat treatment with a hot air dryer as it is. The processing time is set according to the processing temperature.

When the pH during the heat treatment is less than 1, the physical properties of the fiber are significantly impaired. When the pH exceeds 6, the photocatalytic activity is not imparted, so that the present invention cannot be achieved. Further, when the heat treatment temperature is lower than 100 ° C., the processing time becomes longer and is not an industrially advantageous method.
On the other hand, if the temperature exceeds 160 ° C., the physical properties of the acrylonitrile fiber are impaired, which is not preferable.

[0014]

EXAMPLES Examples will be shown below to facilitate understanding of the present invention, but these are merely examples, and the gist of the present invention is not limited thereto. In the examples, parts and percentages are shown on a weight basis unless otherwise specified. The metal ion content and antibacterial performance described in the examples were measured by the following methods. (1) Metal ion content A solution obtained by wet-decomposing a fiber of 0.1 gr with a 95% concentrated sulfuric acid and a 62% concentrated nitric acid solution was atomized using an atomic absorption spectrometer AA855 (manufactured by Jarrell Ash Co., Ltd.). The absorbance was measured and determined.

(2) Antibacterial activity The number of Staphylococcus aureus is 1.5 to 3.0 × 10 ⁶ / m
The bacterial suspension was adjusted to 1 to give a test bacterial solution. 0.2 g of the sample fiber and 20 ml of the test bacterial solution were added to an Erlenmeyer flask, and the mixture was shaken at 30 ° C. for 30 minutes. Then, the number of viable cells was measured, and the residual viable cell rate (LogS (%)) was determined. Here, the remaining viable cell rate is calculated by the following equation, where A is the number of bacteria of the added test bacterial solution, and B is the number of bacteria after shaking for 30 minutes. Residual viability rate (LogS (%)) = Log [(B / A) ×
100] When the residual viable cell rate is 2, it indicates that there is no antibacterial property, and -2 indicates that it has strong antibacterial property (99.99% of bacteria are killed).

In order to examine the photocatalytic activity of the present invention,
The above-mentioned shaking at 30 ° C. is performed under light irradiation (tungsten lamp 100 V, 100 W) and in a dark room, and the value obtained by subtracting the remaining viable cell ratio under light irradiation from the remaining viable cell ratio in the dark room is the residual viable cell ratio. Difference. The value of the residual viability difference is a parameter indicating the photocatalytic activity, and the larger the value, the higher the photocatalytic activity.

Production Example 1 of Acrylonitrile Fiber Containing Antimicrobial Active Metal Acrylonitrile obtained by polymerization according to a conventional method.
An acrylonitrile-based polymer composed of 1%, acrylate methyl ester 8.6%, and sodium methallyl sulfonate 0.3% is dissolved in a 45% strength aqueous solution of rhodan soda.
A spinning dope having a polymer concentration of 12% was prepared. The stock solution was extruded into a 10% rodan soda aqueous solution at −3 ° C. using a well-known die, washed with water, stretched, and heat-treated to prepare an acrylonitrile fiber (fiber A). Then
In order to introduce silver which is an antibacterial active metal into the fiber, 20m
1 ml of silver nitrate aqueous solution adjusted to mol / l
Fiber A in a solution adjusted to pH 3 with a 3% aqueous nitric acid solution.
100 g, treated at 98 ° C. for 10 minutes, washed with water,
After drying, it is poured into 1000 ml of an aqueous solution of sodium oxalate adjusted to 10 mmol / l,
The mixture was treated for 1 minute, washed with water and dried to prepare an acrylonitrile-based fiber containing antibacterial active metal (fiber B).

Production Example 2 of Acrylonitrile Fiber Containing Antibacterial Active Metal Acrylonitrile fiber containing antibacterial active metal, except that a acrylonitrile polymer composed of 95% AN and 5% vinyl acetate was used, and the treatment time with an aqueous silver nitrate solution was 30 minutes. In the same manner as in Production Example 1 of Example 1, an acrylonitrile-based fiber containing antibacterial active metal (fiber C) was prepared.

Examples 1 to 5 and Comparative Examples 1 to 3 The acrylonitrile fibers containing the antibacterial active metal (fibers B and C) obtained as described above were immersed in an aqueous solution whose pH was adjusted with nitric acid, and then drained. Then, it is put into an autoclave (when the heat treatment temperature exceeds 100 ° C.) or a hot air drier (when the heat treatment temperature is 100 ° C. or less), heat-treated at the pH and temperature shown in Table 1, and compared with Examples 1 to 5. Six types of fibers of Example 3 were made. Comparative Examples 1 and 2 are acrylonitrile fiber (fiber A) and acrylonitrile fiber containing antibacterial active metal (fiber B) of Production Example 1 of acrylonitrile fiber containing antibacterial active metal, respectively.

[0020]

[Table 1]

With respect to the fibers of Examples 1 to 5 and Comparative Examples 1 to 3 thus obtained, the antibacterial performance and the residual viability difference represented by the content of metal ions and the residual viability under light irradiation and in a dark room. Table 2 shows the results obtained by measuring and calculating the photocatalytic activity represented by

[0022]

[Table 2]

From Table 2, it is found that Examples 1 to 5 of the present invention
The residual viability ratio difference is 1.2 or more and the residual viability under light irradiation is superior to the residual viability under a dark room, and it has photocatalytic activity. It can be seen that the performance is improved and the residual viable cell rate upon light irradiation is -2 or less, indicating that the composition has excellent antibacterial performance. In particular, Examples 1 and 2 have extremely excellent photocatalytic activity with a difference in residual viability of 1.8 or more, and also have extremely excellent antibacterial performance with a residual viability of -2.4 or less. However, in Example 1, since the treatment was performed under the condition of high acidity of pH 1, the fiber morphology was slightly disturbed, such as partial fusion of single fibers. Example 5 heat-treated at 170 ° C.
Had slightly colored fibers.

On the other hand, Comparative Example 1 containing no antibacterial active metal showed no antibacterial activity and photocatalytic activity, and Comparative Example 2 containing the antibacterial active metal and Comparative Example 3 heat-treated at pH 7
Had some antibacterial performance, but no photocatalytic activity.

According to the present invention, an acrylonitrile fiber containing an antibacterial active metal compound is subjected to a heat treatment in a pH range of 1 to 6 so that the antibacterial property is increased by light irradiation without increasing the amount of the antibacterial active metal compound. It is a remarkable effect that it can provide antibacterial acrylonitrile-based fiber having photocatalytic activity, which can enhance antibacterial properties, and it is suitable for clothing, bedding, interior products, living materials, etc. having cleaner and comfortable antibacterial performance. The use of is expected.

Claims (4)

[Claims] 1. An antimicrobial acrylonitrile fiber having photocatalytic activity obtained by subjecting an acrylonitrile fiber containing an antimicrobial active metal compound to a heat treatment in a pH range of 1 to 6. 2. The antimicrobial acrylonitrile fiber having photocatalytic activity according to claim 1, wherein the antimicrobial active metal compound is a silver compound. 3. The antibacterial acrylonitrile-based fiber having photocatalytic activity according to claim 1, wherein the acrylonitrile-based fiber has an anionic functional group. 4. The antibacterial acrylonitrile-based fiber having photocatalytic activity according to claim 1, wherein the heat treatment is a heat of 100 to 160 ° C. or a heat of dry.